USB drive on Windows Server 2003
Sep 11 2008 - By George Webster
I encountered a odd problem playing with Windows Server 2003 in that by default any external storage media be it flash or other usb drives do not auto-mount. They need to be assigned a drive letter manually.
Which as it turns out is simple.
Right click 'My Computer' -> 'Manage' -> 'Disk Management'. If the device is listed, assign a drive letter to it by right clicking the drive -> 'Change drive letter and paths' -> 'Add..'
(source)